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  • in reply to: Passivhaus Mandatory Critera #39015
    Mark Siddall
    Participant

      Hi John,

      Dave is correct. Speak to your certifer. The main thing with the windows is to avoid the risk of thermal discomfort from down draft and low radiant temperatures. For this reason the internal surfanpce temperature of the window should not fall below 16.4C on the design day (-10C). Whilst the 0.8 W/m2K is a good marker, and in the eyes of PHI applies to the UK, there are arguments for relaxation in the U-value if you are, broadly speaking, “south of Manchester”.

      With regard to install: The position of the window within the wall (between int. and ext. surfaces) and the overlap of the insulation across the frame (where utilised) are key elements, as are the used of equivalent insulation types (cellulose, mineral wool, EPS, XPS etc). Again, firm this up with your certifier before this is set in stone.

      in reply to: Basements #39002
      Mark Siddall
      Participant

        Thanks to Nick Devlin for this link. (Some interesting scientific papers on basement design.)

        http://www.ibp.fraunhofer.de/en/Publications/contributions_to_conferences.html#tabpanel-2

        Mark Siddall
        Participant

          Hi
          Mark Siddall, I'm based in Durham/Newcastle (working between the two for my own practice LEAP – the backronym for Low Energy Architectural Practice – and lecturing at Northumbria Uni). When I'm not doing those things help to I chair the North East regional group. Feel free to email me via the AECB messaging system and I'll do what I can to help.

          Cheers,
          Mark

          in reply to: Window installation Psi value in accordance to the PHI #38947
          Mark Siddall
          Participant

            Tom,I
            What is being discussed is not “PHPP” it is a convention for calculating thermal bridges. This information may then be entered into PHPP. The main thing is that consistent and clear points of reference are used so as to avoid error.

            Thanks for nitpicking though. Error now ammended.

            in reply to: Basements #39000
            Mark Siddall
            Participant

              Jean-Marc,
              I'm not suggesting that there is an issue free basement technology. Ideally I'd like to do is develop a way of assessing and comparing the risks so that the most appropriate solution my be sought. Believe me I'm not one for complication.

              in reply to: Window installation Psi value in accordance to the PHI #38945
              Mark Siddall
              Participant

                I don't understand your question Tom.

                in reply to: Electric or wet underfloor heating #38987
                Mark Siddall
                Participant

                  Hi Peter,
                  Yes, I'm saying that in practice the carbon emissions will be lower with LGP.
                  Here is a good primer by Nick Grant and Alan Clarke: https://aecb.net/publications/biomass-a-burning-issue/
                  (Also check out the thread somewhere on this forum.)

                  in reply to: Window installation Psi value in accordance to the PHI #38943
                  Mark Siddall
                  Participant

                    David,
                    The most important thing is to be consistent in your method and to document this in such a way that another person could replicate the results. Provided that the PHPP model using the psi-values uses the same dimensional methods used in the psi-value calcs then in terms of energy calcs the results will be the same. There are differing interpretations with regard to the appropriate point at which to determine the dimensions – and you cover almost all the bases.

                    EN standards, to which PHI refer, do not offer clarification that the level of detail that you are asking. PHPP refers to the 'rough opening' i.e. the line of structural opening for the window/door.

                    A) Pete Warm (Passivhaus Certifier) prefers this method as he can check dimensions against the window/door manufacturers documentation and use these dimensions in PHPP. Given that he's the certifier and I'm the designer his preference holds sway – so I use this method, however…
                    B) As an architect this is the option that I prefer as it is the actual structural opening and my opening schedules are based upon this dimension
                    C) Not appropriate as this is not the rough opening.

                    Edited 28/08/13

                    in reply to: Re: Re: Kitchen ventilation #38978
                    Mark Siddall
                    Participant

                      Ho Ian,
                      May I suggest that you have a look in the building regulations:

                      http://www.planningportal.gov.uk/buildingregulations/approveddocuments/partj/

                      in reply to: Electric or wet underfloor heating #38985
                      Mark Siddall
                      Participant

                        Hi Pete,
                        A few thoughts:

                        1) It sounds like the chalet MAY be used year round, but may not. Which is more likely? (This could influence the selection of appropriate heating system.)

                        2) I am not comfortable with using high grade energy (elec) for a low grade use (heating water/space). This is really quite inefficient/wasteful.

                        3) Heat losses from the electrically heated cylindar will be lost to the space (thus heating it). If the challete is not perminantly occupied (at normal household levels) then this heat will then be lost to outside with no functional use – so this becomes even more wasteful of the PV energy. If you want to manage this you will need some sort of control system – more complexity, or careful management by the owner.

                        4) It sounds like your carbon emissions, either by (grid) immersion or biomass, will be pretty high comapred to LPG (0.57 kg/kWh elec and about 0.45 kg/kWh biomass). Why not reinevest the capital from the wood stove into upgrading the insulation a condensing boiler and a timer/thermostat and reduce the CO2 emissions for no additional cost?

                        5) What airtightness target are you aiming for? Less then 3 ac/h@50pa?

                        6) What is the ventilation strategy?

                        Mark

                        in reply to: Re: Re: Open forum post #38936
                        Mark Siddall
                        Participant

                          Adam,
                          So join the AECB! The cost is not all that great. The benefits are great (https://aecb.net/membership-benefits/)

                          Mark

                          Mark Siddall
                          Participant

                            David
                            May I suggest that you go on a therm training course. Perhaps the one that is provided by the AECB Carbonlite training course. This should resolve many of the queries y are raising.

                            ATB,
                            Mark

                            P.S. I am a Carbonlite trainer (so could be viewed to have a vested interest.)

                            in reply to: Psi Therm software #38953
                            Mark Siddall
                            Participant

                              Better than therm as calcs psi-values without the need to export to excel.

                              in reply to: Degree-days method #38874
                              Mark Siddall
                              Participant

                                I've already commented on the basic method. And confimed that you are on the right track.

                                ….erm. There is open software available (auditable i.e. in MS Excel format) that can help you to corroborate that you are using an appropriate calculation methodology. This will help you to ensure that the degree day method that you are employing accords with BS EN standards.

                                Mark

                                in reply to: Re: Re: Condensation Analysis Required #38828
                                Mark Siddall
                                Participant

                                  What kinds of condensation analysis are you looking for? If you want the best current standards, using WUFI for example, then Joseph Little is your man. http://www.buildinglifeconsultancy.com/

                                Viewing 15 posts - 16 through 30 (of 915 total)